1#ifndef __NET_DST_METADATA_H
  2#define __NET_DST_METADATA_H 1
  3
  4#include <linux/skbuff.h>
  5#include <net/ip_tunnels.h>
  6#include <net/dst.h>
  7
  8struct metadata_dst {
  9	struct dst_entry		dst;
 10	union {
 11		struct ip_tunnel_info	tun_info;
 12	} u;
 13};
 14
 15static inline struct metadata_dst *skb_metadata_dst(struct sk_buff *skb)
 16{
 17	struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
 18
 19	if (md_dst && md_dst->dst.flags & DST_METADATA)
 20		return md_dst;
 21
 22	return NULL;
 23}
 24
 25static inline struct ip_tunnel_info *skb_tunnel_info(struct sk_buff *skb)
 26{
 27	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 28	struct dst_entry *dst;
 29
 30	if (md_dst)
 31		return &md_dst->u.tun_info;
 32
 33	dst = skb_dst(skb);
 34	if (dst && dst->lwtstate)
 35		return lwt_tun_info(dst->lwtstate);
 36
 37	return NULL;
 38}
 39
 40static inline bool skb_valid_dst(const struct sk_buff *skb)
 41{
 42	struct dst_entry *dst = skb_dst(skb);
 43
 44	return dst && !(dst->flags & DST_METADATA);
 45}
 46
 47static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
 48				       const struct sk_buff *skb_b)
 49{
 50	const struct metadata_dst *a, *b;
 51
 52	if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
 53		return 0;
 54
 55	a = (const struct metadata_dst *) skb_dst(skb_a);
 56	b = (const struct metadata_dst *) skb_dst(skb_b);
 57
 58	if (!a != !b || a->u.tun_info.options_len != b->u.tun_info.options_len)
 59		return 1;
 60
 61	return memcmp(&a->u.tun_info, &b->u.tun_info,
 62		      sizeof(a->u.tun_info) + a->u.tun_info.options_len);
 63}
 64
 65void metadata_dst_free(struct metadata_dst *);
 66struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
 67struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
 68
 69static inline struct metadata_dst *tun_rx_dst(int md_size)
 70{
 71	struct metadata_dst *tun_dst;
 72
 73	tun_dst = metadata_dst_alloc(md_size, GFP_ATOMIC);
 74	if (!tun_dst)
 75		return NULL;
 76
 77	tun_dst->u.tun_info.options_len = 0;
 78	tun_dst->u.tun_info.mode = 0;
 79	return tun_dst;
 80}
 81
 82static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
 83{
 84	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 85	int md_size;
 86	struct metadata_dst *new_md;
 87
 88	if (!md_dst)
 89		return ERR_PTR(-EINVAL);
 90
 91	md_size = md_dst->u.tun_info.options_len;
 92	new_md = metadata_dst_alloc(md_size, GFP_ATOMIC);
 93	if (!new_md)
 94		return ERR_PTR(-ENOMEM);
 95
 96	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
 97	       sizeof(struct ip_tunnel_info) + md_size);
 98	skb_dst_drop(skb);
 99	dst_hold(&new_md->dst);
100	skb_dst_set(skb, &new_md->dst);
101	return new_md;
102}
103
104static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
105{
106	struct metadata_dst *dst;
107
108	dst = tun_dst_unclone(skb);
109	if (IS_ERR(dst))
110		return NULL;
111
112	return &dst->u.tun_info;
113}
114
115static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
116						 __be16 flags,
117						 __be64 tunnel_id,
118						 int md_size)
119{
120	const struct iphdr *iph = ip_hdr(skb);
121	struct metadata_dst *tun_dst;
122
123	tun_dst = tun_rx_dst(md_size);
124	if (!tun_dst)
125		return NULL;
126
127	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
128			   iph->saddr, iph->daddr, iph->tos, iph->ttl,
129			   0, 0, 0, tunnel_id, flags);
130	return tun_dst;
131}
132
133static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
134						 __be16 flags,
135						 __be64 tunnel_id,
136						 int md_size)
137{
138	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
139	struct metadata_dst *tun_dst;
140	struct ip_tunnel_info *info;
141
142	tun_dst = tun_rx_dst(md_size);
143	if (!tun_dst)
144		return NULL;
145
146	info = &tun_dst->u.tun_info;
147	info->mode = IP_TUNNEL_INFO_IPV6;
148	info->key.tun_flags = flags;
149	info->key.tun_id = tunnel_id;
150	info->key.tp_src = 0;
151	info->key.tp_dst = 0;
152
153	info->key.u.ipv6.src = ip6h->saddr;
154	info->key.u.ipv6.dst = ip6h->daddr;
155
156	info->key.tos = ipv6_get_dsfield(ip6h);
157	info->key.ttl = ip6h->hop_limit;
158	info->key.label = ip6_flowlabel(ip6h);
159
160	return tun_dst;
161}
162
163#endif /* __NET_DST_METADATA_H */